


Set Theory

by fishmoth



Category: A Court of Thorns and Roses Series - Sarah J. Maas
Genre: Angst with a Happy Ending, Fluff and Angst, Multi
Language: English
Status: In-Progress
Published: 2018-01-22
Updated: 2018-02-04
Packaged: 2019-03-08 07:25:05
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 4
Words: 7,411
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13453317
Author URL: https://archiveofourown.org/users/fishmoth/pseuds/fishmoth
Summary: I love, love that canon!Mor comes out to Feyre. And I ship Nessian all day long. I don't know how I feel about Elucien vs. Elazriel, but that's okay.Except there's a little part of me that, prior to reading ACOWAR, thought Mor, Cassian & Azriel should end up together, damn the consequences. It's a little predictable, more than a bit fluffy, but I hope you enjoy it!





	1. 1. the intersection of two circles determine a line known as the radical line

Beautiful, brilliant morning sunshine. Golden rays slanting across the room through carelessly half-drawn curtains. Her skin bathed in glorious light, warmth and peace and muscle-memory of careless days under cerulean skies. Sunrise in the summertime, illuminating the reborn world for those fortunate enough to rise in time. Morning dew evaporating, vibrant colours filling the landscape like an artist adding pigment to a sketch, the hot, bright star with which there would be no world bringing its daily renewal of growth and heat and life to Velaris.

Just what she _didn’t_ need after a late one at Rita’s.

Or maybe that should be an early one. Mor groped around the sun-drenched bedsheets, searching for a pillow or a blanket or literally anything to cover her face. Why hadn’t drunk Mor thought to close the curtains? There was no chance of her getting out of bed to do so now. Her fingers closed on soft fabric and she pulled snuggled her face into whatever it was. The cloth smelt vaguely of Cassian and she made a mental note to tell him if he wanted to get ready for nights out at hers, he shouldn’t make such a damn mess. It was probably a shirt he’d discarded for some banal reason like _not tight enough on the upper arms._

Curtain arrangements aside, sober Morrigan usually trusted drunk Morrigan. Drunk Morrigan had good taste in bars, clubs, cocktails, drinking games and men. Especially men. Her memories of nights out were usually hazy, yet interspersed with exhilarating moments of clarity: spinning under enchanted lights, enticing her friends onto dancefloors, genius matchmaking and kisses which hinted somehow simultaneously at starlight and absolute darkness. She had two impressive wingmen, if you could excuse the terrible pun (she’d forbidden them from using that joke to make other ladies giggle about three hundred years ago, claiming she was sick to her back teeth of hearing it even if in truth it still often reappeared in her mind, an old staple she was deeply fond of), and amazing dress sense. Not to mention a figure moulded by half a millennium of working out. If you were going to do something, in Morrigan’s book, you might as well do it right. And that included flings, whirlwind romances and one-night stands.

Although a fleeting glimpse of a clock tower under a heaven of diamond stars which now graced Mor’s memory suggested it had been half three as she and her companions wove their way back to her house, the actual identity of whoever was laid behind her was currently eluding her. Hungover Mor wasn’t worried; she was pretty confident in drunk Mor. She adjusted her position slightly, feeling broader knees against the back of her own, the gentle pressure of a shoulder against her shirt-clad back. That was weird. She was still wearing a shirt… Her fingers found the hem of it, identifying it as one of her own, a simple wine-red shift… hang on a second, she was wearing her own pyjamas. Her decidedly unsexy “night in” pyjamas. What had happened between her and the mystery male that she’d ended up in cosy nightwear?

Keeping her eyes tight shut against the sunlight until she could turn away from it, Mor rolled over to face whoever lay beside her. Her head rebelled, the headache she’d managed to stave off by lying still now starting to demand in earnest to be let in. She liked the mystery, in a way: it was part of the fun. Eyes closed, she slipped her right foot between the male’s calves, tucking it in as she ran her hand down his ribs and back up towards his shoulder blades.

_Wings._

Oh shit. Drunk Mor had brought home an Illyrian. Sure, some of them were drop-dead gorgeous, tan skin and tattoos and gleaming hazel eyes, but she tended to avoid them. Too high a chance that Cassian had beat them in a fight once decades ago and would take the mick out of her for sleeping with someone who’d lost to him.

Reluctantly, Mor opened her eyes to survey the damage. Hopefully he was some big, handsome character from a mountain clan he’d now return to before anyone heard. Although the likelihood that the boys hadn’t noticed who she left with was slim, given it had been the three of them out together the night before. Unless they’d paired off before her. But all hope of that slipped away as another lucid recollection came back to her, of the bar closing and Cassian half taking flight in indignation and being seized round the waist by Azriel as they were finally turfed out by an amused yet forceful bartender.

The tattoos were familiar. Mor felt herself tense immediately. To an untrained eye Illyiran tattoos might all look the same, but there were subtle variations and motifs unique to each warrior. Perhaps in a broader sense Mor didn’t know much about the patterns and whorls etched into Illyrian skin. There were three Illyrians, however, who she’d been seeing shirtless on a regular basis for the last five centuries. Her gaze flickered between elements she recognised, speeding up as she totalled up familiar constellations of ink, recognition hurtling into her mind at breakneck pace as she realised she knew each and every one.

She jerked her face up to see his, half-hidden by the pillow, his dark eyelashes softly closed against tan cheeks.

Azriel.

Her reaction put both of their battlefield responses to shame. Mor sat immediately upright, whipping her feet out from between his legs. The jerking movement woke him up, hazel eyes awash with emotion – joy? surprise? fear? – before they became unreadable again, the spymaster’s eyes. Shadows seemed to boil up from the floor, from the space the sun didn’t reach between the bed and the far wall, eclipsing most of his body.

“Oh Az,” she whispered, drawing in a sharp gasp. “Did we –,”

But the words fell away. She didn’t even know what words she’d want to use.

She moved across the bed, increasing the space between them by a small fraction which felt like a world of distance. Blonde hair fell back around her shoulders as she leaned away, tangles from the night before snarling around the points of her ears. She extended a hand out behind herself in a gesture of rarely-needed support. How had she ended up in bed with Azriel? In four hundred years, they’d always managed to skirt around the way he looked at her, to face every fear except the complex, tangled web which was her and Az and Cassian.

Cassian, who now made a decidedly unmanly noise as Mor’s outstretched hand, bearing the weight of her upper body, collided with his nose.

Cassian, whose also-shirtless body she spun round to recognise as he batted her away, rising from a sprawl of limbs that had been just low enough not to cast a shadow across her face in the morning sun.

Cassian, whose expression went from one of _hungover man rudely awakened before lunchtime_ to one of shock, of confusion, of concern.

“Oh Cauldron,” Mor breathed, waking up fully between the two greatest Illyrian warriors of their age.


	2. 2.generally, every two great circles on a sphere are concentric with each other and with the sphere

**Notes for the Chapter:**

> I'm hooked on writing these guys! Fyi, this fic starts before the books, because I think the three would take a long time to grow into their relationship. The events in the books will come later, although we'll have to split off before any of Mor, Cas and Az end up in any other pairings. Hope you enjoy!

“Oh Cauldron,” Mor breathed, waking up fully between the two greatest Illyrian warriors of their age.

Where seconds before her body had been suffused with glorious warmth a chill now crept insidiously across her flesh. Icy fingers seemed to trace haunting lines down her skin, poor ghosts of the inky designs covering the two males’ chests – chests which until recently she had been curled between, blissful and unaware. A hundred needle-points of sweat seemed to break through her skin simultaneously while her hands and feet, tangled moments earlier in the limbs of the Illyirans, now felt unpleasantly clammy.

_What did we do._

Beyond anything Morrigan had ever felt on the battlefield, ugly, brutal fear coiled in her chest, readying to strike. A wave of nausea crashed over her, the pain in her head intensifying from a drumbeat to the pounding footfalls of marching legions. She looked again between Azriel and Cassian. The shadows Az had subconsciously summoned flickered and writhed around him, obscuring almost all of him from view. Even though he remained perfectly still, physically, she recognised that swirling darkness as his most personal expression of anxiety. On her other side Cassian, usually so brash and ready to fight back against anything, just lay there slack against her pillows. His face had gone unnaturally pale.

_What have we done._

“We just slept,” he answered her straight away, as if he’d heard the question, that same sleep slurring even those short words. But his claim was a question in itself and he gave that away by looking across at the younger Illyrian for an affirmation of the fact. Azriel propped himself up slightly, visibly making an effort to regain control of the darkness around him. It lessened its grip, revealing that he had been sleeping in a worn pair of training pants. The sight of the beaten-up workwear seemed to relax all three warriors by a fraction. Cassian might have had them worried, lying there all tattoos and wings and underwear, but no-one was getting laid in Azriel or Mor’s outfits.

Mor unfolded herself from between them cautiously, her calf barely brushing against Cassian’s leg as she climbed out of bed. Despite his assertion that they had all been _just sleeping_ the touch sent a shiver of unexpected, guilty excitement through her. And chasing that shiver came the fear, returning with a vengeance. How had she possibly ended up in bed with her fellow Circle members? What had changed in the course of a single night?

Cassian was talking again, words spilling from his mouth in a way she knew he only spoke when he was scared. Not that they _did_ scared, really, any of them – but there had been times, before they faced the worst of their opponents, when they squared up to demons they could only battle together, that he’d confessed to his nervousness in pouring, pooling sentences. Only to her and Az. There had been times she’d seen Rhys clasp him on the shoulder or meet his gaze across a campaign table to weigh frightful odds together, but only she and Az heard him like this.

“Shit, guys. We must be getting old. A couple of drinks and we’re just falling into bed together? Officially lightweights.” Only her and Az and Cass. “At least you two got to see the sight of me in pants. Where did you get those sweats, Az?” Only the three of them knew each other like that. “And Mor, seriously, I thought you were going to take home that pretty Peregryn last night. How did you end up with two losers like us?”

He was so scared he was getting his jokes mixed up, claiming to be a blessing to lovers everywhere one moment and her fallback call the next. A wan smile crept onto her face, despite the desperately heavy ache of fear inside her.

Az was next to break the silence, surveying his outfit. “I think these are yours, actually,” he said, frowning, indicating Cassian and the pants. “From your training bag. You had it with you yesterday.”

The three of them peered at the trousers for a moment before realising they were purposefully distracting  themselves. “We just sl-“ Azriel started to repeat, but Cassian had started talking at the same time. “What we need is _breakfast,”_ he insisted, enunciating as if distancing himself from the drunken words and the drunken sleep and the drunken _whatever they might have done,_ however vehemently they seemed bent on denying it now _._ And Mor, making a conscious effort to steel herself and push that fear down, away, deep inside herself, found the courage to say, “It’s always about food with you, isn’t it.”

Azriel snorted, elegant features dismantled and put back together in a contorted expression as he first laughed and became overcome with horror an instant later. Horror, because they all remembered Mor making the same jest in a bar several night ago, and Cassian replying “Food and fighting and fucking, Mor, you know me so well.” And in their present circumstances, none of them could bear to think beyond the middle of that sentence.

Mor met Az’s eyes and bit her lip, turning away to find open her wardrobe and find some proper clothes to put on. Try as she might to force it down the raw terror in her chest remained, threatening to tear up and out of her throat in rending sobs. A technique she was trained in for the battlefield came to her; Mor never failed herself when it came to selecting a weapon, a training regime, a tool to fight with. And here was today’s offering. _What are you really scared of_ , she forced herself to ask and answer. _Face up to what you’re actually afraid of._ To date, her responses had a common theme. _Losing the fight. My friends dying in battle. Losing in front of the others. My family seeing me like this._

Her answer today was not entirely new. She had been afraid of losing Cassian and Azriel before: losing them to arrows or spears or swords. And she’d been scared to let them down when she fought back-to-back with them and entrusted her life to their skill as they trusted her with their own. But never before had she been scared to lose them by her own actions – her own foolishness, letting something as stupid as a drunken night out lead to a mistake which could forever change their friendship.

Losing them by her own hand.

Mor gathered up some training clothes, telling herself firmly that she would work through the hangover– and possibly the emotions, although it was far more tempting just to bury them deep – with a painfully intense workout. She removed herself to the bathing room, pulling off the red shift over her head, surveying the territory of her body in the mirror. No tell-tale marks to suggest they did anything but sleep, at least. Between her fingers the aged fabric of her old nightgown was soft and familiar and her traitorous memory grasped at that, bringing back another glimpse of the night before.

The three of them, mocking and commiserating, something to do with a white-haired female who refused to show an interest in Az – too shy Az, they’d teased him, as the memory came into focus. But Cassian had stumbled drunkenly through the kitchen door and they’d caught him, laughing, propping one another up and staggering through the house together. She’d tipped Cas onto the bed first as if it were the most natural thing in the world and Az had pulled her down with them as he collapsed alongside. He’d turned to her, beautiful, serious face sombre as he asked her if she would mind them all sleeping in her room tonight. And she’d felt such fierce burning joy as she’d told him she wouldn’t let either of them sleep anywhere else.

And then Cassian had roused himself from his hazy-eyed drunken daze and frowned, rising inelegantly to his feet and peering down at the two of them. “You can’t sleep in thooose,” he’d postulated, waving a pointed finger somewhere in the approximate direction of her red beaded dress, Az’s dark tunic. He set off on a careening walk out into the hall and seemed to re-appear instantly – Mor could only guess she’d slumped against Az with her eyes closed – holding his training bag.

“You can borrow _these_ ,” he told Azriel, bestowing the training pants on his comrade-in-arms as though it were a great honour, spilling shirts and vambraces and three daggers in the process. “And Morrigan. Morrigan, you need….”

A further rambling exercise around the room and he produced her shift. “This! This is yours. Put this on.” And he had modestly turned his back so she could change – spinning round an instant later to kick Azriel in the shin so that they could both turn away together.

Suitably attired, Mor had crawled up into the middle of the bed, slipping her bare legs under the soft blankets. Her bed was pretty, thick pieces of carved oak dressed with creamy sheets and a quantity of pillows which pointed towards a decidedly feminine owner. And now it was adorned with Azriel too, tucking himself in beside her as if Cassian were putting them to bed. Only now Cassian was making an awkward flapping motion as he removed his shirt, followed by something which could only be described as _flailing_ to get out of his trousers, catching the tip of one dark wing in the waistband and falling backwards onto the comforter.

Azriel and Mor had clearly made a joint decision that this spectacle was so ridiculous they could be excused for not turning away. Cas had hit the bed on Mor’s other side with an impact that had her fuzzy drunken thoughts wondering whether the ceiling downstairs would look the same tomorrow. And then he’d realised the candles were still lit. “Az, summon… bring the dark, the dark stuff, please,” he’d muttered, burying his head against Mor’s shoulder. But Az had laid flat out already, his breathing slowing and eyelids fluttering, so Mor cast out her with her magic in a rather imprecise net which extinguished the candles and swept several dresses off their hangers in the wardrobe.

Mor blinked at her own reflection in the mirror. The memory had ended, presumably – given the state they’d been in – because she’d fallen asleep. Fallen asleep between her best friends, their winged forms like sleeping guardians on her either side. And despite the violent, primal fear which had filled her when she’d realised who she was with this morning, the memory brought with it a sliver of the deepest happiness.

It wasn’t going to make this morning any easier though, she realised, pulling on her training clothes and splashing water on her face against the hangover. Or tomorrow morning, or next week, or any part of the eternity she’d hoped to spend fighting alongside the two Illyrians ever since she’d got to know them. She wanted to wish it hadn’t happened. But some furtive voice inside her knew that would be a lie. Yes, she was scared, so scared to lose them to a stupid mistake. Only maybe, that small, secretive voice inside her asked with glimmering hope before she pushed the thought away, so far from ready for it: maybe it had not been a mistake.


	3. 3. through any three points, not all on the same line, there lies a unique circle

**Summary for the Chapter:**

> After waking up together one morning, Mor, Cassian and Azriel do their best to pretend nothing had changed in their relationship. But each carries their memories of one another like a gift, kept secret, safe and precious.

**Notes for the Chapter:**

> This chapter is a little longer than the previous two and I really enjoyed writing it! It does cover some canon events so if you've not finished the series you may want to wait before reading this bit. Love and thanks for reading!

Maybe it had not been a mistake.

Four years pass before the trio manage to face up to the night they spent in each others’ encircling arms.

And in those years:

Azriel’s brow is etched with deep folds as he frowns, disentangling the conflicting reports passed on by fleeting spies from the Spring Court. He sighs, knowing that he is too tired to find the kernels of vital information amongst the myriad details. Perhaps another male would abandon the task and leave for his bed, but the weight of these reports lies too heavy across Azriel’s broad shoulders, seeming to push his sinuous grey wings earthwards. Instead of sleeping he brings to mind the next most reassuring thing: the feeling of climbing into Mor’s bed, wrapped in Cassian’s clothes, the memory a mixture of childlike innocence and the thrill of every inch where his body touched hers. In the months after that night he’d called up the memory fearfully, later sheepishly; but now it comes to him as an old friend, offering comfort and companionship in the dark hour before dawn. The recollection of falling asleep besides Mor and Cassian is like a draught which gives him the final strength he needs to work out their rivals’ motives and deliver the crucial findings to the dawn council.

Cassian kicks Azriel under the table in a crowded taproom, a not-so-subtle hint that a fae male at the bar, the one with with chocolate brown hair curling around his delicately pointed ears keeps glancing his way and _you’d be damned stupid not to buy him a drink, Az._ But when his foot hooks around Az’s shin it brings back a heated flash of an image, the moment he had reached out to carefully turn Az towards the wall in Mor’s bedroom. His face colours pink and the other two notice immediately, glancing between one another. It’s rare enough for Cassian to blush but he almost suspects they understand _why_ he’s blushing, which is impossible of course. He pushes the whole group into an outrageous number of rounds, almost dropping the final armload of tankards on his way back to the table in an effort to distract anyone who might somehow have seen him remembering, the jumble of sensory recollections loaded with longing in his mind’s eye. But when he realises Az and the brunette are both missing before the night is over his drunkenness is replaced with a hollow ache he can’t or won’t understand, that no amount of drink or dancing or music can cure.

Mor is looking through a chest she keeps in a little-used room of her home. There is an old sketch, drawn by a painter who was commissioned to portray the Steward of the Hewn City and his young family. The likeness of Mor is in the form of a child and she is smiling, pointed ears and coltish limbs a little askew despite the formal poses they’ve assumed for the portrait. It’s the most bittersweet thing in her universe, this picture, because her family are yet to betray her for the single sin of being born a woman and she can still remember moments of gleaming happiness which have tarnished under the touch of what came after.

The chest is heavy, leather-covered, with a lid that stays shut easily, but not all the memories in it are so terrible they need locking away. Some are only kept with such care because they are precious. There is an incredibly worn set of Illyiran leathers, her first, gifted to her by her fellow Circle members. A cracked Siphon which Rhys broke when he’d first tried to train with them. She’d picked it up just because it seemed wrong to leave something so pretty in the mud, forgetting it immediately and finding it much later in her pocket. A firedrake charm on a fine silver chain which Amren had given her in a moment of rare solicitude.

It’s when she lifts the armour out that another bittersweet memory strikes, rising through the sea of thoughts like an ancient monster – fascinating, in a way, but fearful also. She and Cassian are alone in the house Rhys’ mother used to inhabit by the training camp. The alliance her family have pinned on her – pinned through her, like lances or spears – by promising her to Eris and his father feels like the bars of a cage, binding her untouched golden skin, biting into her flesh. This is what iron would feel like, if it really affected the fae how humans believed it did. She had argued, begged, demanded, cursed, to no end. Her duty – she felt sick remembering they’d called it her _purpose_ – was to marry Eris and found their courtly alliance by bearing his red Autumn heirs.

She remembers the moment it dawned on her, the coiling formulation of her escape plan as she lay alone in bed under the oppressive weight of her future. Her mother had explained in definitive terms how _pure_ she must remain for her wedding, how the Autumn court would only accept a _sacred_ union for which she must be _whole_ and _clean_. Somehow Mor had doubted that Eris was paying her the same respect, whilst simultaneously reflecting on the perversity that her virginity was somehow a necessary component of _respect_. Males were allowed to do as they pleased and no-one called them out for disrespect or impiety. It took a great force of thought, an early exercise of that willpower and self-affirming strength which later came to define her character, to decide that her mother’s idea of purity was one she could put aside.

And in freeing herself from that chattel, she could free herself from Eris.

Perhaps in the back of her mind she’d known it wasn’t just Eris she would escape: this action, which her family would claim as their betrayal despite that it should have been an experience belonging only to her and whoever she chose to share it with, would rid her of her family and the Hewn City and the Court of Nightmares also. But it was Eris in the forefront of her thoughts as she hatched her scheme, Eris and the cruel fate he represented that she was determined to get away from when she resolved to sleep with Cassian.

She’d had to wait several months until it was just the two of them, her hopes rising with a fluttering anxious heartbeat every time there was any reason for the others to go out together. Finally, only weeks before her wedding, it had happened. Rhys and his mother had left first leaving her and Cassian to eat their evening meal with Azriel. She remembered that anxiety, its metallic taste in her mouth. For some reason she’d thought that saying farewell to Az before he set off would give her plan away, so she’d made a point to be busy in the bathing room when he too left.

After that the details faded, blurred by the passage of time, until she was pushing open the door into the main living space. Cassian was sprawled on the couch, his training armour swapped for a more casual tunic and trousers. He glanced up when she came in but didn’t say anything, returning his attention to his task: tooling Illyrian symbiology into the leather of a new baldric. He still did that now, Mor reflected several hundred years later, the image of Cas now replacing twenty-something Cas for a flickering instant.

She remembered shutting the curtains, cursing her hand for the slight tremor it betrayed as she tugged on the heavy fabric. Her whole body was on edge; she’d thought he might be onto her when she closed out the night and the camp, because young Mor had made such an effort not to be domestic, as if this would let her family forget she wasn’t a son and heir.

Cassian had still been frowning at the leather in his hands when she turned though, pausing before he scraped a little curl away with the awl. The moment seemed to stretch on and on before she gave up on him noticing her, padding softly across the floorboards until she was right in front of him. She remembered leaning down and willing her hands not to shake as she gently took the piecework away and met his gaze. She remembered laying the leather carefully to one side and stepping between his knees, lowering her lips to his. She remembered her hair swinging forwards to brush heavily on the angular lines of his jaw, remembered seeing surprise and warmth and willing in his eyes before she shut her own and pressed her mouth to his.

Mor hadn’t known how to kiss. Her lips felt utterly clumsy for the first few minutes. Cas was, thankfully, an obviously willing tutor. One of his hands, already calloused by then, had found her waist, the other her hip. And before she could let fear in through the door to change her mind she’d moved forwards and into his lap, folding her legs around either side of him.

She didn’t know, even now, what he’d thought when she started out that evening. When his right hand had moved to cup her breast and she’d shyly unbuttoned his shirt, when he’d lifted her dress between kisses and she’d unbuckled his belt. She remembered the way that warmth and eagerness in his hazel eyes had coloured with concern as she hurt, unable to keep the first moments of pain from her face. He’d known then; she’d seen him realise what she was doing. She had known he was understanding that she’d betrayed him, albeit a gentle and willing betrayal. She’d made him part of her escape from the Court of Nightmares that evening in the Illyiran war camp and he hadn’t even known to stop her until it was too late.

There was fear in his eyes, fear that she’d appreciated was for her, for what this would mean for her, but she couldn’t let him ruin her plan. She was sorry as she moved her hips against him, bringing longing fiercely back to the surface of his gaze, burying the hurt in pleasure and heat and the touch of their tongues. He’d let her do that; let her lead him into their rhythm, before a low wordless sound escaped him and he’d rolled her over on the low couch and kissed her collar bones and her pointed ears and her cheekbones as he made an effort to go slowly, so plainly not wanting to hurt her more than this certainly would.

Afterwards, she’d allowed them a few moments of warmth nestled against each other before she tried to smile for him. There were no words she could use to express how she felt and what he’d done for her; she wanted the smile to thank him and apologise for using him and actually, also, to tell him that she’d picked him because he was one of the greatest warriors she knew and against all the odds he’d taken her to a lasting instant of aching blissfulness. But tears pricked behind the smile and she could only meet his gaze for a moment before she left, her gown falling back over her hips, hair against her shoulders as she walked away.

She told herself it didn’t matter that it had been Cassian. It didn’t matter who would be next, either. All that mattered was that it wouldn’t be Eris and a marriage bed and a fiery heir to the Autumn Court in her womb.

But laying alone again in her bed that night the tears had returned in force, welling up in gouts that spilled from under her golden lashes and brought sobs that she fought to keep silent rising up through her throat. She cried because she had forced herself to use Cas, to sleep with him as a means to an end and not because she loved him like that. With time, she thought, she might have loved him or Az or someone else and given herself freely, without costing them the knowledge that they were ruining her as they freed her. But there was no time; she was desperate; it had been the best and only plan she could come up with to escape her family’s intentions.

Further memories flashed before her as she sat on the floor holding her old leathers. Forcing herself to meet Cassian’s eye as they ate breakfast the next morning, because not to do so would be cowardly and Mor refused to be a coward. His smile, a mixture of happiness and young, masculine pride and sadness because he knew, somehow, that what they’d done had been part of a plan that would hurt her as it helped her. Back in the Hewn City a week later, when she’d told her mother. Barefaced. _I told you I wouldn’t marry Eris, mother, and I shan’t,_ she’d announced in their rooms. Her mother had sighed and laid down her sewing as if ready to repeat her usual remonstrations but Mor had stopped her with that single truth. _I’m not a virgin, so he won’t want me anyway._

And then the mirror of her memories shattered, vanishing into blackness and fragments of pain. Hundreds of years it may have been, but she didn’t want to relive what came next.

She skipped ahead, to when she’d been able to put the leathers she now cradled in her arms back on. That was a better memory full of power and strength and healing.

It was Cas’s eyes in her mind that kept her from forcing the whole thing away entirely; the kindness that had been there, even alongside the lust and desire and youthful glee that Mor had wanted him. As she grew up and took other lovers she’d wondered if she could have saved him from being the one to damn her and free her. But back then she’d have hated to take a stranger to bed, hated to let some hard, vicious male from the camps or the court take what she wanted to give freely, willingly. She regretted using Cas and yet she was eternally grateful to him.

Again, Cas in the memory became Cas in a far more recent one and she inhaled sharply, dropping the leathers as in her mind he drunkenly buried his head in her shoulder, Az’s hand gently touching her other side as he fell asleep against her.

Just because something was bittersweet in one memory, didn’t mean you shouldn’t build on it with another, not when the _other_ brought such a rush of heated emotion.

It may have taken her the best part of forty decades to let Cas back into her bed and bring Az into that place where he belonged with them, but now she realised with that intake of fresh air that she didn’t want to wait forever to do it again.


	4. 4: set theory examines whether an object belongs, or does not belong, to a set of objects which has been described in some non-ambiguous way

**Summary for the Chapter:**

> Mor comes to a realization, while Azriel gets into trouble watching Cassian training.

**Notes for the Chapter:**

> Okay, so I feel like very little actually _happens_ in this chapter. But it's important, I think, and hopefully not painful to read!
> 
> I also appreciate I've spent more time focused on Az and Mor than Cassian. He's going to get some attention soon I promise! Rhys and Amren will also show up soon, because although these guys are super fun to write, they aren't the only people in Velaris.
> 
> Thank you again for reading! Much love to everyone who commented/liked so far <3

She didn’t want to wait forever to do it again.

Mor rose quickly to her feet, her trove of possessions forgotten. She crossed to the window, looking out blindly over the side street a storey below. Fae bustled past heading to and from the centre of Velaris, but she didn’t see their passing, only the distant mountains, their horizons indistinct against a washed-out expanse of blue winter sky above.

How would she tell them? Although after the first time Cassian had made it gently obvious that he was interested in repeating what had passed between them, she’d rebuffed him every time. Probably with a little too much force, but she hadn’t been able to scrub away the feeling that she’d used him and that had showed in her rejections. And she’d been forceful with Az, too, when he tried to tell her how he felt. She could remember the way the dappled golden light had fallen on the fine bones of his face, hazy through the pain, as he gathered up her broken self at the border of the Autumn Court. And later he’d come back to her, that beautiful expression anxious, afraid, earnest, and she’d known what he was about to say. Known and wanted to hear it but also, somehow, aware that she couldn’t hear it. Not like that. So she’d turned away in a moment of uncharacteristic cruelty and pretended there was no feeling there, even to herself.

 _Not like that._ Even then, barely into her twenties, had she realised there was a way she might have wanted to hear it?

But if she wanted to hear it from both of them, only in conjunction with telling the two of them how she felt –

Mor stopped seeing even the bleak expanse of sky, shocked immobile at what her subconscious had just freely admitted.

**~~~**

Beside the training ring, Azriel set the whetstone to the blade once again, trying to focus on the task. The tool sang with a sound that was somehow simultaneously smooth and gritty, honing the edge of the sword to a fine cutting edge.

It was a welcome distraction from the action in the open space to his left. Four of the most promising recruits from the Illyiran mountain clans had come to train with Cassian. Apparently this was some sort of reward for their prowess to date. Az personally felt that this was the sort of perverse logic peculiar to Illyrian commanders: you did well, so you can go get beat up by someone you’ve got no chance against. But in truth a session with Cas could be invaluable to them. He pushed them hard into drills and skirmishes where every strike was a lesson, ever moment their guard failed or their attention slipped made a vital point of learning.

Cas wouldn’t get them for long, and he needed to teach them as much as he could. One day on the battlefield it might be something he fitted in to these fleeting hours that saved their lives.

Az glanced up again at the youngsters as they trouped over to drink water and take a moment’s rest.  The comparison to his own brotherhood was obvious: he doubted he and Rhys and Cas had stopped arrogantly flapping their wings at one another like that and jibing at each other’s weaknesses until the age of at least a hundred. In fact, it wasn’t like they’d ever stopped completely, but watching these four he realised they had matured in comparison.

His attention turned to Cas, who was striding over to where he was sitting at the side of the arena. “You’re out of excuses, Az,” grinned his friend. A broad wave of his muscular arm took in the newly sharpened swords in the rack by Az’s workspace and the almost-ready blade in his hands. “Going to join us now?”

Az, however, had other plans for his afternoon. He still trained daily with Cas but he also found preparing the weapons oddly soothing. For the last few centuries, he’d not only maintained his own, but also the personal caches of weaponry that all the members of the Inner Circle kept at the House of Wind. It was satisfying; somehow, above all the intel and the carefully crafted network of spies and the reports back to Rhys, it was this that made him feel useful.

“I’ve got plenty of excuses left,” he replied in that soft, deep voice that called to mind the whispering darkness he could summon in an instant. He paused in his work, looking over to the wrapped weapons stacked by the stairway up from the House. “Mor’s, Amren’s, some neglected ceremonial sword Rhys forgot he owned.”

One of the young Illyirans looked up sharply at that, recognising the names of the women in the Inner Circle. Of course, Az thought: in his comparison to their younger selves, the fourth warrior would have been Morrigan. But even now the Illyirans are obviously surprised to hear a female’s name as he listed the owners of the blades. For a moment he felt a bitter anger that had first risen inside him when he learned Mor was destined to marry Eris. Despite her escape, the anger had only grown as he saw what it had cost her, saw the way some of the commanders sneered at her, saw the distaste in her father’s eyes in the Hewn City.

But Cauldron, she could cut down her enemies when she had to. Mor was a warrior unparalleled by most of Prythian and he’d fight anyone who said otherwise – except she’d probably beat him to it.

Az tried to push away the thought of Mor in her fighting leathers by returning to the present, meeting Cas’s gaze. Ever since he’d embraced the memory of their night together as an old friend, his two companions seemed to twine into his thoughts with increasing frequency. And where once he would have been focussed, little points about them both had become distracting. It was all very well trying not to picture Mor in that supple, dark fabric, but a damn sight harder to ignore Cas in the same getup right in front of him.

For a second, he thought he saw something reflected in Cas’s eyes, but his brother-in-arms’ smirk returned and Cas simply said, “You’ll get rusty yourself, old man,” before turning away. Az watched him every step of the walk back to his trainees.

**~~~**

Despite the scale of his self-appointed sharpening task, Az found it hard to keep his attention from slinking back towards Cassian as the other male shouted orders to the trainees. They flagged, slightly at first then more evidently, faces gleaming with perspiration as the commander pushed them towards their limits. Ever the good tutor, Cas noticed, moving their exercises on to defensive stances and effective blocking methods.

The stab of jealousy caught him unawares, a sick feeling twisting unexpected in his gut. One of the trainees had gradually revealed through the course of the afternoon that his balance was slightly off; Cas was now working to correct the young Illyrian’s stance. The commander firmly rearranged his pupil’s pose, swiftly but effectively correcting the potentially fatal irregularity.

It held none of the meaning that Az’s subconscious seemed determined to read into it, but the envy was there all the same: a hot, ugly feeling that made him want to rise up and rush the trainee every time Cas’s hands came into contact with the younger male.

This was ridiculous. He forcibly turned his eyes back to the dagger he was working one, an artistically shaped yet practical knife of Amren’s, inlaid with her usual level of sparkle. But as he went to run the stone down its length his hand shook for a second, anger manifesting as tendrils of darkness to swirl around the blade. He had _nothing_ to get angry about, nothing to make him feel this way. Before he was even aware of moving his traitorous gaze had returned to Cas; he was quite unable not to notice how the other male held his wings perfectly folded as he demonstrated the techniques his students were to perfect.

Az had always held himself to a high standard of mental discipline, but suddenly his mouth was dry. He couldn’t cope with this. He had no idea why, suddenly, he felt an uncontrollable desire to tell the trainees that their time was up – an important report had come in and he required the Commander of the Night Court’s armies to respond to it immediately. And then, once they were alone, to –

 _To what_ , he asked himself. _What, exactly, would you do next, Azriel? You don’t even know._

He put the dagger down with uncharacteristic carelessness and dropped the tools beside it, wings snapping together in a poor mockery of Cas’s honed position as he stalked off the rooftop training ring. In the stairwell, shadows flocked so thickly to him that he could barely see the steps. He was thankful not to meet anyone, friends or staff or visiting dignitaries, as he made his way to his private rooms only half-conscious of his surroundings. What had led him to become so confused, so overwhelmed by emotion?

He locked the door behind him and sank onto a chair, dropping his head into his hands. With Mor, his feelings were obvious, if not exactly easy. He had loved her from those first few weeks of knowing her. It was a simple fact, a pure and wholesome truth that he had buried deep but never forgotten. She’d turned away from him all those years ago, it was true, so he hadn’t pushed it – but equally, she’d never told him never, and Az held a surprising capacity for hope.

But with Cassian…

Azriel’s first few weeks with Cassian were fraught with pain and injury. He forgave the other male for beating him up when they met: that was basically how Illyrian recruits said good morning and had been quickly forgotten. But it was hard for warm feelings to grow when you were a useless, earthbound child compared to your new companions. To be sure, their feeling of brotherhood had grown as Rhys and Cas taught him to fly; but with every wingbeat, every minute gain in altitude and improvement in aerial manoeuvrability, there was hurt and burning shame.

Speculatively, he tried out the idea that he’d given up on Mor and fallen into an equally painful trap with Cas. But it didn’t fit; his feelings for the blonde heiress to the Hewn City hadn’t changed. If anything, they felt stronger, somehow more honest. But there was no denying the longing he now felt when he looked at his fellow Illyrian; no ignoring the closeness and affection in that perfectly preserved memory of the three falling sleep curled around one another.

Unable to hold out against this strange revelation, Azriel allowed the swirling darkness to fill the room completely.


End file.
